Effect of pump parameters on the emission of PbSe quantum dot-doped optical fiber considering Auger recombination

Abstract

The deficiency for quantum dots (QDs) used as optical amplified medium (such as QD-doped fibers) is nonradiative Auger recombination based on multiple exciton state, which is related to pump power, pump frequency, and pump wavelength. Thus, the Auger recombination lifetime was introduced in the existing three-level system, further the emission of PbSe QD-doped optical fiber as a function of pump parameters mentioned above was simulated in order to maximize emission intensity and optical gain. The emission intensity increased first and then saturated with the pump power, showing good agreement with the experimental data. An optimal pump power maximizing the emission intensity was observed, which is distinguished from the non-Auger decay-result that the emission intensity increased with the pump power in a linear way. The emission intensity increased with the increasing pump frequency (from 4 to 10 × 10 4 Hz). In addition, 532-nm pump light was confirmed to enhance the output intensity compared to the other longer wavelengths. The relationship between emission intensity and pump fluence is similar to that of the experimental data. The maximal optical gain of 11.5 dB was obtained. The threshold pump power decreased with the increasing pump frequency, in which situation, larger pump power was needed to achieve the optical gain saturation. This research might be a theoretical basis for QD-doped optical fiber amplifiers and lasers.